/*-----------------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date:        19. March 2015
* $Revision: 	V.1.4.5
*
* Project: 	    CMSIS DSP Library
* Title:        arm_iir_lattice_init_q15.c
*
* Description:  Q15 IIR lattice filter initialization function.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
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*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
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*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* ---------------------------------------------------------------------------*/

#include "arm_math.h"

/**
 * @ingroup groupFilters
 */

/**
 * @addtogroup IIR_Lattice
 * @{
 */

/**
 * @brief Initialization function for the Q15 IIR lattice filter.
 * @param[in] *S points to an instance of the Q15 IIR lattice structure.
 * @param[in] numStages  number of stages in the filter.
 * @param[in] *pkCoeffs points to reflection coefficient buffer.  The array is of length numStages.
 * @param[in] *pvCoeffs points to ladder coefficient buffer.  The array is of length numStages+1.
 * @param[in] *pState points to state buffer.  The array is of length numStages+blockSize.
 * @param[in] blockSize number of samples to process per call.
 * @return none.
 */

void arm_iir_lattice_init_q15(
    arm_iir_lattice_instance_q15 *S,
    uint16_t numStages,
    q15_t *pkCoeffs,
    q15_t *pvCoeffs,
    q15_t *pState,
    uint32_t blockSize)
{
    /* Assign filter taps */
    S->numStages = numStages;

    /* Assign reflection coefficient pointer */
    S->pkCoeffs = pkCoeffs;

    /* Assign ladder coefficient pointer */
    S->pvCoeffs = pvCoeffs;

    /* Clear state buffer and size is always blockSize + numStages */
    memset(pState, 0, (numStages + blockSize) * sizeof(q15_t));

    /* Assign state pointer */
    S->pState = pState;


}

/**
 * @} end of IIR_Lattice group
 */
